New findings from research from the Texas A&M University School of Public Health indicate that exposure to even low levels of arsenic poses significant health risks, including an increased risk of kidney cancer.
The incidence of kidney cancer in the United States increased by an average of 1.2 percent each year between 2011 and 2019 to become the seventh most common cancer. Meanwhile, smoking (a well-established risk factor for kidney cancer) has continued to decline.
This led researchers to consider other possible contributing factors, including arsenic, a known cause of several cancers that occurs naturally in groundwater in Texas and other areas. Unlike previous studies, the Texas A&M study focused on low levels of arsenic exposure (below the regulatory threshold of 10 parts per billion) in both public water systems, which are regulated by several government agencies, and in private well systems, which are not regulated.
“Some public water systems are poorly managed and could expose customers to arsenic, but the 40 million people in the United States who rely on private wells are particularly vulnerable,” said Taehyun Roh of the Department of Epidemiology and Biostatistics.
Others involved in the study were Daikwon Han, Xiaohui Xu and then-PhD student Nishat Tasnim Hasan, from the Department of Epidemiology and Biostatistics, and Garett Sansom, from the Department of Environmental and Occupational Health. The project was supported by grants from the Houston Methodist Research Institute, the Robert and Janice McNair Foundation, and the National Institute of Environmental Health Sciences.
Their findings, published in Environmental pollutionexamined the relationship between kidney cancer rates and arsenic levels in drinking water in 240 Texas counties. The team analyzed cancer data from Surveillance, Epidemiology, and End Results on 28,896 cancer cases among Texas adults age 20 and older, along with water testing data from the Texas Department of State Health Services and the Development Board. of Texas Water.
They used a statistical model that takes geographic location into account and adjusted the model based on demographic and socioeconomic factors and cancer risk factors such as obesity, smoking and diabetes. They also adjusted for covariates including pesticide density, social vulnerability, income level, rurality, cardiovascular disease hospitalization rates, and prevalence of chronic kidney disease.
The analysis found that exposure to between 1 and 5 parts per billion increased the risk of kidney cancer by 6 percent, and exposure above 5 parts per billion increased the risk by 22 percent. Additionally, the risk of cancer increased by 4 percent with each doubling of arsenic levels in the water.
“This suggests that even low levels of arsenic exposure in drinking water may be associated with an increased risk of kidney cancer, which is consistent with previous research indicating an association between this exposure and lung, bladder and skin cancers.” “Roh stated.
Hasan noted that his study design may indicate associations between factors but not causation and recommended that future studies focus on individual-level and biometric data, rather than the county-level data used here, to better assess the effects of factors. like lifestyle. , family history of kidney cancer, and other possible sources of arsenic exposure.
“Still, our findings indicate that reducing arsenic exposure could reduce the incidence of kidney cancer, and this could be achieved through efforts such as improved regulatory oversight and targeted public health interventions,” Hasan said.